This invention relates to pulse detonation systems, and more particularly, to a rotating valve for high temperature and high pressure operation in a pulse detonation combustor.
With the recent development of pulse detonation combustors (PDCs) and engines (PDEs), various efforts have been underway to use PDC/Es in practical applications, such as in aircraft engines and/or as means to generate additional thrust/propulsion. Further, there are efforts to employ PDC/E devices into “hybrid” type engines, which use a combination of both conventional gas turbine engine technology and PDC/E technology in an effort to maximize operational efficiency. Other examples include use in aircrafts, missiles, and rockets.
Pulse detonation combustors are used, for example, in pulse detonation engines. In pulse detonation engines, thrust is generated by the supersonic detonation of fuel in a detonation chamber. The supersonic detonation wave increases the pressure and temperature in the detonation chamber until it is released resulting in thrust. As with any engine that intakes air, inlet stability is an important aspect of maintaining proper operation of a pulse detonation engine. This presents a particular challenge in pulse detonation engines, which use open inlet tubes.
The operation of pulse detonation engines creates extremely high-pressure peaks and oscillations within the combustor that may travel to upstream components, and generates high heat within the combustor and surrounding components resulting in damage and malfunction of the upstream components. Consequently, various valve techniques are being developed to provide inlet control and prevent the high-pressure peaks from traveling to the upstream components.
Because of the recent development of PDCs and an increased interest in finding practical applications and uses for these devices, there is an increasing interest in increasing their operational and performance efficiencies, as well as incorporating PDCs in such a way so as to make their use practical.
In some applications, attempts have been made to replace standard combustion stages of gas turbine engines with a single PDC. However, it is known that the operation of PDCs creates extremely high-pressure peaks and oscillations both within the PDC and upstream components, as well as generating high heat within the PDC tubes and surrounding components. Because of these high temperatures and pressure peaks and oscillations during PDC operation, it is difficult to develop operational systems, which can sustain long-term exposure to these repeated high temperature and pressure peaks/oscillations.
Further, because of the need to block the pressure peaks from upstream components, various valving techniques are being developed to prevent high pressure peaks from traveling upstream to the compressor stage. However, because of the frequencies, pressures and temperatures experienced from PDC operation the use of traditional valving is insufficient. Inadequate valving can cause unsteady pressure oscillations that can cause less than optimal compressor operation.
In addition, high reliability and long life (5000 to 10000 hrs life) for commercial applications is a challenge for PDE applications and has not yet been demonstrated.
Therefore, there exists a need for an improved method of implementing PDCs in turbine based engines and power generation devices, which address the drawbacks discussed above.